Portable electronic device

ABSTRACT

A portable electronic device  100  includes a horizontally long casing, both ends of which are gripped by a user&#39;s both hands, respectively. The device further includes a LCD fit into the front face of the casing  10 . Outwardly projecting bulges are respectively formed at both sides of the rear face of the casing where fingers of the user gripping the casing  10  placed. Since the fingers and palms are naturally flexed to fit to the dome-like bulges  42 L,  42 R, the portable electronic device  100  fits comfortably in the user&#39;s hands. The operability is hard to be degraded even if the device is vibrated strongly during a game play with the device.

TECHNICAL FIELD

The present invention relates to a structure of a portable electronicdevice, and in particular, to a structure for improving the operabilityof the portable electronic device.

BACKGROUND TECHNOLOGY

Recently various types of gaming products have been developed and theyoccupy a high position in entertainment field. In particular, portablegaming devices become popular recently and a user can enjoy playinggames with the device anywhere.

DISCLOSURE OF THE INVENTION

Various types of portable electronic devices such as portable gamingdevices and personal digital assistances (PDAs) are developed. Many ofthem have a casing taking shape similar to a rectangular solid. When auser plays a game with the portable electronic device, it is difficultfor the user to grip the casing, and low operability of the devicereduces interest in the game. There is another problem that the user'shands become fatigued easily when the user grips the casing ofrectangular shape for a long time.

It is a general purpose of the invention to provide a portableelectronic device having an easy-to-operate shape by a user.

One embodiment of the present invention relates to a portable electronicdevice comprising a horizontally long casing, both ends of which arecapable of being gripped by a user's both hands, respectively, and adisplay unit fit into the casing, wherein outwardly projecting bulgesare respectively formed at both sides of the rear face of the casingwhere fingers of the user gripping the casing placed.

According to the embodiment, since the fingers and a palm of a user arenaturally flexed to fit to the dome-like bulges on the rear face of thecasing, it is easy to grip the portable electronic device. And theoperability is hard to be degraded even if the portable electronicdevice is vibrated strongly while a game is being played with thedevice. In addition, the portable electronic device fits comfortably inthe user's hands. Therefore, even if the user grips the portableelectronic device for a long time, the user feels hardly tired.

The casing of the portable electric device may be a resin molded part.The resin molded part comprises a transparent window through which thedisplay unit can be viewed and a frame other than the transparentwindow. The transparent window is made of a first transparent resin. Theframe is made from a second colored resin. The first resin and thesecond resin are preferably molded in a unified fashion by two-colormolding. As such, by molding the transparent window and the frame in aunified fashion, strength of the casing may be ensured.

The first resin may be molded to cover whole surface of the frame in theresin molded part of the casing. Thus, uniform surface without a joint,a step, or a gap on the surface of the casing may be formed, which addsto the beauty.

The portable electronic device may comprise a speaker within the casing.A through hole may be formed at the bottom face of the casing foremitting sounds generated from the speaker. The through hole may beformed with an angle toward the front face of the casing. Thus, soundsare emitted toward the face of the user gripping the portable electronicdevice.

The portable electronic device may comprise a second through hole formedin the front face of the casing, and a duct formed inside the casing fordirecting sounds generated from the speaker to the second through hole.Thus, the user feels such that sounds are output from the front face ofthe casing. So, high realistic feeling is realized.

Any combination of elements stated above is also effective as oneembodiment of the present invention.

According to the embodiments, the operability of a portable electronicdevice may be improved because of bulges are provided on a back face ofa casing of the device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a portable electronic device according tofirst embodiment;

FIG. 2 is a top view of the portable electronic device according tofirst embodiment;

FIG. 3 is a rear view of the portable electronic device according tofirst embodiment;

FIG. 4 is a bottom view of the portable electronic device according tofirst embodiment;

FIG. 5 is a left side view of the portable electronic device accordingto first embodiment;

FIG. 6 is a right side view of the portable electronic device accordingto first embodiment;

FIG. 7 shows a resin molded part for an upper part;

FIG. 8 shows a frame of the upper part;

FIG. 9 is a view showing how the portable electronic device is grippedby both hands of the user;

FIG. 10 is a functional block diagram of the portable electronic device;

FIG. 11 shows structure of speakers;

FIG. 12 shows a headphone jack and a remote controller jack;

FIG. 13 is a front view of a portable information device according tosecond embodiment;

FIG. 14 is a top view of the portable information device according tosecond embodiment;

FIG. 15 is a rear view of the portable information device according tosecond embodiment;

FIG. 16 is a front view of a first variation of the portable informationdevice according to second embodiment;

FIG. 17 is a front view of a second variation of the portableinformation device according to second embodiment;

FIG. 18 is a front view of a third variation of the portable informationdevice according to second embodiment; and

FIG. 19 is a front view showing the working of the portable informationdevice in FIG. 18.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

FIGS. 1 through 6 are views showing the appearance of a portableelectronic device 100 according to one embodiment of the presentinvention. FIG. 1 is a front view of the portable electronic device 100.A casing 10 has a horizontally long oval shape as a whole. Each end ofthe casing 10 is formed in a circular curve shape with its centerdecentered from a center line 14 by a certain distance.

As shown in FIGS. 2 and 4, the casing 10 is composed of an upper part 10a, an intermediate part 10 b, and a lower part 10 c. Inside the casing10, a circuit board (not shown) is provided. The circuit board includes:switch contacts for generating a signal by the operation of variouscorresponding buttons; a central processing unit which processes thesignals so as to execute various computations; an image processing unitfor executing image process; and a sound processing unit for executingsound process. The circuit board (not shown) is secured to the upperpart 10 a or the lower part 10 c. The intermediate part 10 b has ahigher rigidity than those of the upper part 10 a and the lower part 10c to ensure the rigidity of the entire casing 10.

Returning to FIG. 1, a liquid crystal display 12 (hereinafter,abbreviated as an “LCD 12”) serving as a display device is fit into thecenter of the casing 10. The LCD 12 displays, for example, a game screenwhen the portable electronic device 100 functions as a game machine ordisplays a schedule or an address list when the portable electronicdevice 100 functions as a personal digital assistant (PDA).

FIG. 7 shows the shape of the upper part 10 a. The upper part 10 a is aresin molded part. The LCD 12 and various buttons mounted on the circuitboard are covered by the upper part 10 a. The upper part 10 a comprisesa transparent window 102 and a frame 104. FIG. 8 shows the frame 104. Asubstantially rectangular space for the transparent window 102 is formedin the frame 104. Holes 106, 108 where the various buttons are looselyinserted and holes for checking the LEDs therethrough are also formed inthe frame 104.

The transparent window 102 is made of transparent resin material forprotecting the LCD 12 and for enabling the LCD 12 being viewed throughthe window. The frame 104 is made of a colored resin material to concealthe circuit board from view. The transparent window 102 and the frame104 are molded in a unified manner by two-color molding technology,which molds two resins of different colors or materials at the sametime. More specifically, after injecting a colored resin material forforming the frame 104 into a mold form, a transparent resin material forforming the transparent window 102 is also injected into the mold form.At that time, the transparent material is molded to cover not only thetransparent window 102 but the whole surface of the frame 104 (that is,the surface viewed by the user gripping the portable electronic device100) except for the button holes like a thin film. Thus, uniform surfacewithout a joint, a step, or a gap between the transparent window 102 andthe frame 104 is formed, adding to the beauty and improving thevisibility of the LCD 12 through the transparent window 102.

Regions of the frame 104 situated above and below the transparent window102 (that is, a decorative area 16 and a button area 50), is very narrowas shown in FIGS. 7 and 8. Therefore, by performing the two-colormolding, strength of the upper part 10 a become improved when comparedto the structure that a transparent sheet is attached onto the LCD forprotection or the structure that transparent sheet is fit into the frame104. Since the user sometimes pushes strongly the surface of the casingof the portable electronic device for button operation, the casingshould have certain strength. By molding the transparent window and theframe in a unified manner according to the embodiment, strength can beensured. In addition, since the transparent window 102 and the frame 104can be molded in a unified manner at the same time, molding cost may bereduced. Further, by coating the whole surface of the frame 104 with atransparent resin material, surface with luster appearance may beacquired, which adds to the beauty.

As the resin materials, polycarbonate resin with shock resistance andtransparency is preferable, but other resin such as acrylic may beemployed. The transparent window and the frame may be molded indifferent resin materials from each other.

Returning to FIG. 1, the surface of the upper part 10 a of the casing10, that is, the front face being opposite to the user is mainlycomposed of: a left-hand area 48L gripped by the left hand of the user;a right-hand area 48R gripped by the right hand of the user; the LCD 12;a horizontally long button area 50 positioned below the LCD 12, wherevarious buttons are provided; and a decorative area 16 positioned abovethe LCD 12. Notches 84L and 84R are formed on an upper left corner andan upper right corner of the upper part 10 a of the casing 10,respectively.

In the left-hand area 48L, an arrow key 20 mainly for inputting adirection instruction and an analog device 22 mainly for analog input ofthe direction instruction are provided. The detailed structures andfunctions thereof will be described below. Indicators 32 and 34 are alsoprovided in the left-hand area 48L. The indicator 32 lights up duringaccess to a removable recording medium, and the indicator 34 lights upduring wireless LAN (WLAN) communication.

The analog device 22 is located on the device closer to the user thanthe arrow key 20. The horizontal center of the analog device 22 islocated closer toward the center line of the casing 10 than thehorizontal center of the arrow key 20. The reason for this arrangementis as follows. When the left thumb of the user moves between the arrowkey 20 and the analog device 22, the user pivotally moves his thumb withhis palm on the lower left corner of the casing 10 as a supportingpoint. And the user tilts the center of the analog device 22 foroperation. Therefore, the operation is facilitated when the analogdevice 22 is positioned closer to the center of the casing 10.

In the right-hand area 48R, buttons 30 a, 30 b, 30 c and 30 d(hereinafter, also collectively referred to as “button keys 30”) areprovided mainly for inputting a unique instruction. A structure andfunctions of the button keys 30 will be described below. Additionally,indicators 36 and 40 are provided in the right-hand area 48R. Theindicator 36 lights up when the portable electronic device 100 is ON.The indicator 40 lights when the portable electronic device 100 is in ahold status where every key of the portable electronic device 100 isinvalid.

As shown in FIG. 1, the center of the arrow key 20 and the center of thebutton keys 30 are preferably shifted upward in the vertical directionfrom the horizontal center line of the casing 10.

The center of the arrow key 20 and the center of the button keys 30 arepreferably located at the same distance from the center line 14 of thecasing 10 in the horizontal direction. Each distance between pressedfaces 20 a, 20 b, 20 c and 20 d on a disk-like key top of the arrow key20 is preferably set smaller than that between the buttons 30 a, 30 b,30 c and 30 d. The reason for this arrangement is as follows. Since thearrow key 20 is mainly used to direct the vertical and horizontalmovements, the user often keeps operating the arrow key 20. Therefore,it is preferable to set the distances between the pressed faces 20 a, 20b, 20 c and 20 d of the key top so that the user can operate the arrowkey 20 without taking his thumb off the pressed faces of the arrow key20. On the other hand, the button keys 30 are often used to givedifferent instructions by respective buttons 30 a, 30 b, 30 c and 30 d.Therefore, it is easier for the user to operate taking his thumb off thebutton keys 30. Hence it is preferable that the buttons 30 a, 30 b, 30 cand 30 d are located with a certain distance so as to avoid pressingunintended button with a tip of the thumb when the user places his/herthumb on one button.

At both ends of the transparent window 102 of the upper part 10 a, afront-face through hole 28L is provided in the left-hand area 48L, and afront-face through hole 28R is provided in the right-hand area 48R.

The button area 50 is located in the vicinity of an outer edge of theupper part 10 a of the casing 10 on the side closer to the user holdingthe portable electronic device 100. In the button area 50, buttons 52 to64 are located other than the arrow key 20, analog device 22 and buttonkeys 30. Preferably, the button area 50 is constituted so as to bevisually distinct from the left-hand area 48L and the right-hand area48R. In this embodiment, the button area 50 is formed in a horizontallyextending elongated hill-like shape. The button area 50 is elevatedabove the level of the plane formed by the left-hand area 48L, theright-hand area 48R and the LCD 12. In the vicinity of the top of thehill, various buttons 52 to 64 are provided. With this arrangement, theuser can visually distinguish the buttons to be operated during gameplayor an application operation from the other buttons. Furthermore, sincethe button area 50 is elevated, the user can be tactilely aware of thearrangement of these buttons 52 to 64. The elevated shape of the buttonarea 50 also serves to protect the LCD 12.

The structure of the button area 50 is not limited to theabove-described structure. Any structure may be employed as long as theheight of the button area 50 differs from the height of the left-handarea 48L and the right-hand area 48R. Herein, the “height” means aheight based on a horizontal plane, on which the casing 10 is placed sothat the upper part 10 a is oriented upward. For example, an elongatedstep having a trapezoidal or rectangular cross section may be providedto arrange the various buttons 52 to 64 thereon. Alternatively, wallshaving the height equal to or greater than height of top of the buttons52 to 64 may be provided above and below the buttons 52 to 64 arrangedon the same plane with the left-hand area 48L, the right-hand area 48Rand the LCD 12. With these walls, the buttons 52 to 64 are not easilypressed down by the user's hands operating the arrow key 20 or thebutton keys 30.

It is preferable that the buttons 52 to 64 (also referred to as “suboperation buttons”) arranged in the button area 50 are not frequentlyused for gameplay or a main operation of the other applications, andtherefore the buttons 52 to 64 are not required to be frequentlypressed. Specifically, a home button 52 is used to go 12 back to a mainscreen. A volume buttons 54, 56 serve to decrease/increase the volume ofa sound reproduced through a speaker or a headphone, respectively. Adisplay button 58 turns ON/OFF a backlight of the LCD 12. A sound button60 turns ON/OFF a sound output. A select button 62 serves for selectingone item from items displayed on the LCD 12. A start button 64 mainlyserves to start a game when a game program is being executed.

In a conventional portable electronic device or game controller, buttonsstated above are not provided on the plane different from the plane withthe arrow key or the button keys as this embodiment, but provided belowthe arrow key or the button keys, for example. With such conventionalarrangement, when the user operates the arrow key or the button keys,the finger of the user carelessly touches such buttons, sometimesleading to an erroneous operation. On the other hand, according to thisembodiment, since the various buttons are arranged on the plane distantfrom the arrow key or the button keys, erroneous operations are reduced.

Notches 86L and 86R are also formed on the lower left corner and thelower right corner of the upper part 10 a of the casing 10 as on theupper left corner and the upper right corner. Below the notches 86L,grip parts 87L are provided. A hole 24 is formed in the grip part 87L toallow a strap (not shown) or the like to be passed therethrough andtied.

When the portable electronic device 100 according to this embodiment isused, the forefingers are placed on the top side face of the casing 10so that the left thumb is placed above the arrow key 20 or the analogdevice 22 and the right thumb is placed above the button keys 30, asdescribed with reference to FIG. 9. The other fingers are placed so asto cover dome-like bulges on the rear face of the casing 10. In thismanner, the curve formed by the forefingers fits to the shape of theleft and right side faces of the casing to help the user's grip. At thesame time, the weight of the casing 10 is kept by the middle fingers tothe little fingers. Therefore, even if the thumb or the forefinger ismoved for operation, the remaining fingers can stably support theportable electronic device 100.

FIG. 2 is a top view of the portable electronic device 100. As describedabove, dome-like bulges 42L and 42R (hereinafter, also collectivelyreferred to as “bulges 42”) are formed on both ends of the rear face ofthe casing 10. A plane is formed between the two bulges 42. Almost theentire plane is a lid 44 of a small disk drive unit. One end of the lid44 is pivotally supported to the lower part 10 c of the casing. Bysliding a switch 76 provided in the intermediate part 10 b, another endof the lid 44 opens backward of the portable electronic device 100. Asmall disk drive unit (not shown) is housed in the casing under the openlid 44. A small disk can be loaded on the disk drive unit. The smalldisk provides an application program or a game program for the portableelectronic device 100. Most of mechanical parts of the small disk driveunit such as optical pick-up (for example, a lens and servo system) arepositioned under the right half part of the LCD 12 in FIG. 1.

An L-button 46L and an R-button 46R (hereinafter, also collectivelyreferred to as “LR-buttons 46”) are buttons respectively operated by theleft forefinger or left middle finger and the right forefinger or rightmiddle finger of the user. The LR-buttons 46 are preferably used forgiving a special instruction that cannot be commanded only with thearrow key 20 or the button keys 30. For example, when a game screen isdisplayed on the LCD 12, the LR-buttons 46 may be operated for a specialaction of a character in the game (for example, a fighting stance or asquatting position), firing a special weapon and the like.

By providing the dome-like bulges 42 for grip on the rear face of thecasing 10, the fingertip of the user is unlikely to touch the lid 44 ofthe small disk drive unit, preventing a large force from being appliedto the disk drive unit. Furthermore, the dome-like bulges 42 areprovided on both ends of the rear face of the casing 10. Therefore, evenif the portable electronic device 100 is placed on a plane, the lid 44of the small disk drive unit does not come into contact with the plane.Further, since the impact to the small disk drive unit become smaller,stable operation of the disk drive unit is ensured, leading to decreaseread errors.

As can be seen from FIG. 2, the tops of the arrow key 20 and the buttonkeys 30 are higher than the maximum height of the transparent window 102of the upper part 10 a when the casing 10 is placed on a horizontalplane so that the face without the LCD 12 is oriented downward.Therefore, even if the casing 10 is placed so that the face with the LCD12 is oriented downward, surface of the transparent window 102 over theLCD 12 is not worn. Furthermore, as shown in FIG. 2, the casing 10 has acircular curve cross section so that its thickness decreases from itscenter toward both ends. The arrow key 20 and the button keys 30 arearranged so as to be inclined toward the ends of the casing 10 inaccordance with the cross-sectional shape of the casing 10. Thisarrangement helps the user to grip the casing 10 and improves theoperability of the arrow key 20 and the button keys 30.

In the intermediate part 10 b of the casing 10, an input terminal 70 foran external device and attachment holes 74 for fixing the externaldevice to the casing 10 are provided. Using the input terminal 70 forconnection with the external device, the portable electronic device 100can be used as an input device for a personal computer or the like inplace of a key board or a mouse, for example. Connection with theexternal device will be further described later in detail. A switch 76for opening the cover of the small disk drive unit and an infrared port88 for infrared communication module are also provided in theintermediate part 10 b.

FIG. 3 is a rear view of the portable electronic device 100. Asdescribed above, the dome-like bulges 42R and 42L are provided on theboth ends of the rear face of the portable electronic device 100.Between the bulges 42R and 42L, the lid 44 of the small disk drive isprovided. The dome-like bulge 42R also serves as a lid for a battery box(not shown). By pressing down an oblong projection 43 and sliding thebulge 42R leftward (direction to the end of the portable electronicdevice 100), the bulge 42R is detached from the casing and replaceablebattery in the casing shows up.

FIG. 4 is a bottom view of the portable electronic device 100. Asindicated with a dotted line in FIG. 4, speakers 80L and 80R areprovided in the casing 10. In front of the speakers 80L, 80R,bottom-face through holes 26L, 26R are formed on the intermediate part10 b, respectively. A plug 82 for a code 84 connected to a headphone ora remote controller is inserted into jacks. The jacks will be describedlater with reference to FIG. 12. On the right of the upper part 10 a, aterminal 66 for supplying DC power to the portable electronic device 100is provided. On the right of the intermediate part 10 b, electrodes 78are provided for supplying electric power from a so-called “cradle” tothe portable electronic device 100 when the portable electronic device100 is placed on the cradle. Projections of the cradle are inserted intothe bottom-face through holes 26L, 26R for supporting the portableelectronic device 100 when the device 100 is placed on the cradle.

FIG. 5 is a left side view of the portable electronic device 100. A WLANswitch 90 is provided in the intermediate part 10 b, and an insert slot92 for receiving a removable recording medium is provided in the lowerpart 10 c. FIG. 6 is a right side view of the portable electronic device100. A power switch 94 for switching ON/OFF the portable electronicdevice 100 is provided in the intermediate part 10 b.

FIG. 9 is a view showing how the portable electronic device 100 isgripped by the user. The portable electronic device 100 is basicallyoperated while being held by the user's both hands. The right and leftends of the casing 10 are held by the right and left hands,respectively. As shown, the user's left hand is slightly flexed to holdthe casing 10 along the arc shape of the left side face of the casing10. At this time, the left thumb of the user is placed on the arrow key20 to operate the arrow key 20. Similarly, the user's right hand is alsoslightly flexed to hold the casing 10 along the arc shape of the rightside face of the casing 10. The right thumb of the user is placed on thecenter of the button keys 30 to operate the button keys 30. Only theuser's forefingers or forefingers and middle fingers are slightly flexedand are placed on the LR-buttons 46. The LR-buttons 46 are operated bythe forefingers or middle fingers.

The user's middle finger, ring finger and little finger, or ring fingerand little finger are put on the rear face of the casing 10 while beingslightly flexed to support the weight of the portable electronic device100. As described above, the dome-like bulges 42 are provided at bothends of the rear face of the casing 10 so as to fit to the curve of theuser's fingers. For example, the dome-like bulges 42 are made of aplastic material. A slip-resistant material such as a rubber or a metalmaterial for texture may be used. Each of the dome-like bulges 42 has asmooth arc cross section as shown in FIG. 2 or FIG. 4. Alternatively,steps may be put on the bulges 42 for receiving the user's fingers, or aplurality of small protrusions may be formed on its surface to improvethe resistance against slip. The bulges 42 make it easier to grip theportable electronic device 100. Therefore, even if the device 100 isvibrated strongly by the user while a game is being played with thedevice, the operability is hard to be degraded. Moreover, since thefingers and a palm are naturally flexed to fit to the arc shape of bothends of the casing 10 and to the dome-like bulges 42 on the rear face ofthe casing 10, the portable electronic device 100 fits comfortably inthe user's hands. Therefore, even if the user grips the portableelectronic device 100 for a long time, the user feels hardly tired.Furthermore, since the weight of the portable electronic device 100 issupported by the middle fingers, ring fingers and little fingers, theportable electronic device 100 can be stably held even when the userreleases his thumb or forefinger off the buttons.

FIG. 10 is a functional block diagram of the portable electronic device100. When the arrow key 20, the buttons 30 a, 30 b, 30 c, 30 d, theL-button 46L, and the R-button 46R are pushed down, a digital signal inresponse to the push operation is input to the central processing unit180 via interface (shown as “I/F 190” in FIG. 10). Other buttons notshown in FIG. 10 are same. When the user takes his/her finger off thebutton, the button comes back to its original position. Operation of theanalog device 22 is converted into a digital signal, and input to thecentral processing unit 180 via I/F 190. Input signals into the infraredmodule 88 and the WLAN module 90 is input to the central processing unit180 via I/F 190. Sound input to the microphone 142 is converted into adigital signal, and is input to the central processing unit 180. Whenthe remote controller 140 is operated, a digital signal depending on theoperation is input to the central processing unit 180 via I/F 190. Thesmall disk drive unit 186 and memory 188 is connected to the centralprocessing unit 180. The central processing unit 180 processes variousinput signals with application software program recorded on the diskloaded on the small disk drive unit 186 or stored in the memory 188, andoutputs image signals and audio signals as a result of the process. Theimage processing unit 182 treats output image signals to display imageson the LCD 12. The sound processing unit 184 treats output audio signalsto make sounds over the speakers 28 or the headphone 144.

The portable electronic device 100 has a plurality of functions. As anexample, the portable electronic device 100 functions as a game machine.The user inserts a disk storing a game program therein onto the smalldisk drive unit 186 provided on the rear face of the casing 10 to play agame. More specifically, when the power switch 94 is turned ON afterloading the disk, the game program is read out from the small disk todisplay a start screen on the LCD 12. When the start button 64 ispressed in this state, the game starts. When the user operates the arrowkey 20, the analog device 22, or the button keys 30 to select menu itemsor to operate a character displayed on the screen, the input signal istransmitted to a central processing unit 180. The central processingunit 180 makes the game progress in accordance with the input signalsand the game program.

In another example, the portable electronic device 100 also functions asa music player. The user loads a disk storing music data therein ontothe small disk drive unit 186 or inserts a removable recording mediuminto the slot 92 to listen to recorded music. In this case, the useruses the arrow key 20 or the analog device 22 to select a title of thesong from the titles displayed on the LCD 12 which the user would liketo listen to. The selected music data is converted into analog sounds bya sound processing unit 184 to be output from speakers 28 or a headphone144.

The functions of the portable electronic device 100 are not limitedthereto. The portable electronic device 100 may have functions such asan address list, a schedule, a memo pad, an E-mail communication, andthe like as is the case of a conventional personal digital assistant(PDA).

The overall configuration of the portable electronic device 100according to this embodiment has been described above. Next, theconfiguration and the function of each main component will be describedin detail.

1. Arrow Key

The arrow key 20 gives a discrete direction instruction for eightdirections, that is, up, down, right and left, plus four directionsbetween them. As shown in FIG. 1, the arrow key 20 comprises the convexpressed faces 20 a, 20 b, 20 c and 20 d corresponding to four directions(up, down, right, and left) on the surface of the disk-like key top. Thedisk-like key top is tiltably supported by a supporting point 20 e atthe center of the key top, which is able to tilt in the eightdirections. A deformation member, a conductive member, and a switchcontacts are provided below each of the pressed faces 20 a, 20 b, 20 cand 20 d. When any one of the pressed faces 20 a, 20 b, 20 c and 20 d ofthe arrow key is pressed down, only the switch contacts below thepressed convex face is turned ON. The arrow key 20 is used to move acharacter in the vertical and horizontal directions in the game or toselect an item from those listed in the menu screen. Since each of thepressed faces 20 a, 20 b, 20 c and 20 d of the arrow key 20 is formed ina convex shape, the user can perform a desired operation withoutdirectly viewing the arrow key 20. Since the top of the convex faces isformed to be higher than the maximum height of the transparent window102 of the upper part 10 a, the surface of the transparent window 102over the LCD 12 can be protected from wearing even when the casing 10 isplaced as the LCD 12 is oriented downward. Moreover, since the disk-likekey top is slant toward its center in a cone shape, it is easy to putthe thumb on the center to ensure the operation of the arrow key 20.

2. Analog Device

The analog device 22 is used to continuously give a directioninstruction in 360 degrees. The analog device 22 includes a hole 22 aformed in the front face of the casing 10, an operation pad 22 b, anddetection means (not shown). The operation pad 22 b passes through thehole 22 a and is constructed to be longitudinally and horizontallymovable in the hole 22 a. The operation pad 22 b is made of, forexample, a rubber. The detection means converts the amount of movementand the direction of movement of the operation pad 22 b into an electricsignal.

The operation pad 22 b of the analog device 22 is biased toward thecenter of the hole 22 a by a spring or the like. When the user does notoperate the operation pad 22 b, the operation pad 22 b is positioned inthe center of the hole 22 a. In operation, the user can tilt theoperation pad 22 b in 360 degrees. Since the stroke of the tilting isset to about 2 mm, the user can tilt the operation pad 22 b for minuteinput to great input.

With such a structure, the portable electronic device 100 according tothe embodiment can realize the game controller with same functions asthose of a so-called “joystick” and have high operability in spite ofits small size.

The input transmitted by the detection means as an electronic signal isconverted into a digital signal by an analog/digital converter providedon the circuit board (not shown), which is then transmitted to thecentral processing unit 180. The central processing unit 180 performs acomputation based on the program to display images on the LCD 12 inaccordance with the user's input.

The input from the arrow key 20 and the input from the analog device 22may be easily switched by the software process. Alternatively, an analogswitch for switching the input between the arrow key 20 and the analogdevice 22 may be provided on the portable electronic device 100.

3. Button Keys

As shown in FIG. 1, the button keys 30 are composed of the buttons 30 a,30 b, 30 c and 30 d. On the surfaces of cylindrical key tops of thebuttons 30 a, 30 b, 30 c and 30 d, circle, triangle, square, and crosssigns are printed, respectively. These buttons 30 a, 30 b, 30 c and 30 dare used to input a single instruction. The deformation member, theconductive member, and the switch contacts described above are providedbelow each of the buttons 30 a, 30 b, 30 c and 30 d. When any one of thebuttons 30 a, 30 b, 30 c and 30 d is pressed down, only the switchcontact just below the pressed button is turned ON. The correlationbetween the type of input and each button key differs depending on thetype of the game program or the application running on the portableelectronic device 100. For example, the buttons keys are used for inputsuch as an attack in a game, item acquisition, menu screen display, itemselection, or response to inquiry.

Each button key is arranged with predetermined spacing between thebutton keys so as to be placed at the four apexes of the square, asshown in FIG. 1. Therefore, if the user extends the right thumb, theuser can operate the triangle button and the square button on the farside when viewed from the right hand side without changing the grippingposition of the casing 10. When the right thumb is flexed, the user canoperate the circle button and the cross button on the close side whenviewed from the right hand side. For identification of each of thebuttons, protrusions or grooves and the like corresponding to circle,cross, triangle, and square signs may be provided on the surfaces of thebuttons.

4. LR-Keys

Recent video games require complicated operation. So, operation meanssometimes would be short only with the arrow key and the button keys.Therefore, many controllers provide the L-button and R-button so as toincrease the number of operation means. In the portable electronicdevice 100 according to this embodiment, the LR-buttons 46 are providedon the top side face of the intermediate part 10 b of the casing 10 asshown in FIGS. 1 and 2. The LR-buttons are press-type buttons. When theLR-buttons 46 are not pressed, the LR-buttons 46 exhibit such appearancethat the LR-buttons 46 constitute a part of the intermediate part 10 b.Moreover, as described above, the LR-buttons 46 are provided at thepositions that the fingertips of the forefingers touch when the usergrips the casing 10.

By the way, when a game creator conceives the game contents, he/she musttake the operability of a controller into account. In this sense, thefunctions of the controller and the game contents are in close relationwith each other. In other words, the game contents are often restrictedby the functions or the operability of the controller. The portableelectronic device according to this embodiment has the operation buttonsincluding the arrow key, the analog device, the button keys, and theLR-buttons, which are equivalent to or superior to the functions of thecontroller of a stay-at-home type game machine although its size iscompact. Since a conventional portable game machine is not equipped withvarious operation buttons, the feasible game contents are restricted ora game program is required to be changed when some stay-at-home typegame is ported to the portable game machine. In the portable electronicdevice according to this embodiment, however, such problems do notarise. Thus, the sphere of creation by game creators can be expanded.

Operating means such as the arrow key, the button keys, or the LR-keysfunction as man-machine interface between the user and the portableelectronic device, which is very important for the user during a gameplay. In other words, the operability of the casing or the functionalityof the operating means of the portable electronic device is very linkedto easy-to-play gaming and the fun of gaming. According to theembodiment, the portable electronic device can be provided having highoperability and high extensibility in spite of its size capable of beinggripped by both hands of the user.

5. Speakers

The portable electronic device 100 can output sounds from the front-facethrough holes 28L, 28R on the front face of the casing 10 and from thebottom-face through holes 26L, 26R on the bottom face of the casing 10.

As shown in FIG. 4, the speakers 80L, 80R outputting sounds are providedone by one on either side near the bottom face of the casing 10. Thespeakers 80L, 80R are placed substantially perpendicular to the bottomface of the casing 10. The speakers 80L, 80R are placed for outputtingsounds to bottom direction of the casing 10. The bottom-face throughholes 26L, 26R are placed in front of the speakers 80L, 80R in theintermediate part 10 b. Sounds from the speakers 80L, 80R are emittedoutside of the casing 10 through the bottom-face through holes 26L, 26R.The bottom-face through holes 26L, 26R are formed with an upper angletoward the front face of the casing 10 such that sounds come toward theface of the user gripping the portable electronic device 100.

As shown in FIG. 11, ducts 98L, 98R are formed inside the casing 10having a route from backside of the speakers 80L, 80R to the front-facethrough holes 28L, 28R. With these ducts, part of sounds output from thespeakers 80L, 80R is emitted toward the face of the user gripping thecasing 10. Thus, the user feels such that sounds are output from thefront face of the casing 10. So, high realistic feeling is realized.These ducts may be designed as so-called bus reflex structure foremphasizing bass sounds.

Since sounds are emitted to two different directions from four throughholes on the front face and the bottom face of the casing 10, therealistic feeling may be improved. By these four through holes, soundswith surrounding effect may be output from the portable electronicdevice 100.

6. Headphones

FIG. 12 shows the casing 10 with plug 82 of a headphone (not shown)detached from jacks. A circular jack 146 is a jack for outputting soundsto the headphone and a rectangular jack 148 is a jack for inputting froma remote controller (not shown) and a microphone (not shown). The plug82 has two different shaped terminals for being inserted to the jack 146and 148, respectively.

7. Input Terminal and Power Terminal

As mentioned above, the input terminal 70 for external device andattachment holes 74 for fixing the external device to the casing 10. Theportable electronic device 100 according to the embodiment may be usedinstead of, for example, an existing keyboard or a mouse as inputtingdevice to a personal computer or so by using the input terminal 70 to beconnected to the external device.

In some cases, the input terminal 70 cannot supply power to the externaldevice from the portable electronic device 100. When external devicesuch as a camera is attached to the portable electronic device 100 forreceiving data input from the external device, power terminals 72 may beprovided on either side of the input terminal 70 for supplying power tothe external device from the portable electronic device 100.

The external device may include a camera unit or a GPS unit. With acamera unit, the portable electronic device 100 may be used as generaldigital camera. In addition, the portable electronic device 100 may beused as a game screen by displaying the face of the user gripping theportable electronic device 100 on the LCD 12. Further, the portableelectronic device 100 may be used for recognizing the user's bodilymovement shot by the camera as game input. With the GPS unit, theportable electronic device 100 may be used as handheld-type GPS locatorfor providing location guidance or record of user's movement history tothe user. In addition, a keyboard or a cellular phone module can beconnected to the input terminal 70.

Second Embodiment

FIG. 13 shows a front view of a portable information device according toanother embodiment of the invention. As shown, the portable informationdevice 200 comprises a LCD 210, a small stick 212, an analog/digitalselecting switch 214, main buttons 216, a center board 250, a frontcover 260, a left recess 280, and a right recess 282.

The LCD 210 is positioned in central part of the portable informationdevice 200 for displaying game images or movie contents. Display of LCD210 is adjusted with predetermined luminance and color tone such thatthe user can view the displayed contents through the front cover 260described later. The small stick 212 can be slanted for any direction of360-degree, which realizes joystick function with its compact body. Theslanted degree of the small stick 212 is acquired as input strength inanalog manner. The analog/digital selecting switch 214 is a switch forthe user to select analog or digital input from the small stick 212 inaccordance with a need for the operation of a game or so. The mainbuttons 216 are buttons printed with circle, triangle, square and cross,respectively, each having a certain function. The main buttons 216 aredisposed at a position of top, bottom, right and left part of a samecircle, respectively. The small stick 212 and the main buttons 216 areused for operating a game character, for example.

The LCD 210 and built-in parts such as a CPU (not shown) are mounted ona center board 250. Outer rim of the center board 250 protrudes from thecasing defined with the front cover 260 and a back cover 270 describedlater. Since the center board 250 is made of material having certainhardness such as metal, bending stiffness of the casing may beincreased.

The front cover 260 is put on the front side of the center board 250 andcovers built-in parts on the center board 150. The front cover 260 ismade of material with predetermined transparency and a color, forexample a resin such as polycarbonate. The front cover 260 is molded ina unified manner. With polycarbonate having a protection effect againstultraviolet rays, the center board 250 and the built-in parts may beprotected against direct light or so when the portable informationdevice is used in the open air. The front cover 260 made of such a resinhas a predetermined color and transparency. Therefore, the user can viewdisplayed contents on the LCD 210 with luminance adjusted describedabove through the front cover 260. Thus, no transparent window needs tobe formed in the casing as a conventional portable information device.Therefore, since unity of the front cover is realized, the device mayprovide novelty impression to the user. The front cover 260 may be castfrom metal such as aluminum. In this case, the shape of the front coverneeds to be appropriately changed for ensuring the visibility of the LCD210.

The portable information device 200 is gripped with both hands or onehand by the user. The shape of the portable information device 200 isconfigured such that a forefinger of the user is placed on a top faceand a thumb of the user is placed on a front face.

On the front cover 260, substantially circular left recess 280 isprovided with the small stick 212 as its center. Inside thecircumference of the circle where circle, triangle, square and crossprinted main buttons 216 are positioned, the right recess 282 isprovided. Peripheral areas around the left recess 280 and the rightrecess 282 have predetermined size such that a user can hang the tip ofhis/her thumb on the fringe of the recess. Since the user can grip thecasing with his/her thumb hanging on the left recess 280 and the rightrecess 282, the user can hold the portable information device stably andoperate the device easily. In addition, even if the user takes his/herthumb off the joy stick when operating the small stick 212, the user canhang the thumb on the recess at once to hold the portable informationdevice 200. So, the recess has an advantage to prevent falling of thedevice.

Further, since the main buttons 216 are arranged at the peripheral areaaround the right recess 282, the user's thumb for operating the mainbuttons is received in the recess naturally. Thus, the portableinformation device 200 is easily held with the thumb hanging the recess,increasing holding stability of the device.

The left recess 280 and the right recess 282 are arranged at symmetricposition in the front face of the casing as shown. The user can grip theportable information device more naturally with the recesses. Inaddition, the front cover 260 has a gentle curve slanted to both rightand left ends of the casing such that the whole casing comprisessubstantially spindle shape as shown. The left recess 280 and the rightrecess 282 are placed on a left slope and a right slope, respectively.With such arrangement, when the user's thumb is received in the recess,pushing power of the thumb directs to the center of the casing. Thus,the user can hold the portable information device 200 more stably.

FIG. 14 is a top view of the portable information device 200 accordingto the second embodiment. As shown, the portable information device 200further comprises a disk cartridge slot 220, group of media reproductionbuttons 222, a small USB connector 224, a left shoulder switch 226, aright shoulder switch 228, an eject button 230, and a back cover 270.

Into the disk cartridge slot 220, a disk cartridge storing gamesoftware, movie contents, or music contents or so is inserted. The groupof media reproduction buttons 222 is provided in a part surrounded inbroken line in FIG. 14. The details of group of media reproductionbuttons 222 are also shown in enlarged version for better understanding.The group of media reproduction buttons 222 is a group for controllingthe reproduction of music contents or movie contents, which includes aplay button, a fast-forwarding button, a fast-rewinding button, a stopbutton and a suspending button in a left-to-right fashion. The small USBconnector 224 is a connector for connecting a personal computer or so tothe portable information device 200, for example. Each of the leftshoulder switch 226 and the right shoulder switch 228 is mainly operatedby a forefinger of the user, which is used for operating a gamecharacter same as the small stick 212 and the main buttons 216 describedwith reference to FIG. 13. The eject button 230 is a button for ejectinga disk cartridge inserted into the disk cartridge slot 220.

The back cover 270 is put on the back side of the center board 250. Theback cover 270 and the front cover 260 define the casing of the portableinformation device 200. The back cover 270 is also made of resin ormetal same with the front cover 260. However, it is preferable that theback cover 270 is made of material having a certain frictionalresistance. By employing material with raising fabric on its surface orwith such finishing on its surface for example, friction is made betweenuser's hand and the material. With such material, gripping feeling isincreased. Such material functions as antislip when the portableinformation device 200 is gripped by hands, enabling stable holding. Inanother example, the back cover 270 may be made of leather or rubber,for example.

FIG. 15 is a back view of the portable information device 200 accordingto the second embodiment. As shown, the portable information device 200further comprises a battery 232, a transparent member 234, a stand 236,a memory slot 238, and an AC adapter jack insertion slot 240.

The battery 232 supplies power for drive the portable information device200. The battery 232 is configured to be detachable from the portableinformation device 200. The user charges the battery by a batterycharger (not shown). In another example, the battery 232 is fixed to theportable information device 200. In this case, the battery may becharged by the AC adapter (not shown) through the AC adapter jackinsertion slot 240 described later. The transparent member 234 isprovided such that the user can view the operating state of the diskcartridge by the user. Thus, the user can view the rotation of the diskcartridge loaded in the disk cartridge slot 220 described in FIG. 14.This also contributes to good design of the device. The stand 236 is atwo-support-type member for standing the portable information device 200on a table so that the user can view movie contents or so instead ofholding the device 200 by hands. The memory slot 238 is an insertionslot for a recording medium storing contents such as game, movie ormusic. To the AC adapter jack insertion slot, a jack of the AC adapter(not shown) is inserted for directly acquiring power for driving theportable information device 200 without the battery 232 from home powersupply, for example. As stated above, this AC adapter may be used tosupply power to the battery 232.

FIG. 16 is a front view of a portable information device 300 accordingto a first variation of the second embodiment. Only a difference withFIG. 13 is described herein. In this variation, four corners of thecasing and four corners of the center board 250 projecting from thecasing have a round shape. With this, when the user operates the leftshoulder switch 226 or the right shoulder switch 228 (not shown) byhis/her forefinger, the casing fits comfortably in his/her hand and theuser can operate the switches without discomfort. The shape of wholecasing is designed roundly, so fresh impression can be provided.Furthermore, two-support-type gripping part 312 is housed in either sideof the casing 10 of the portable information device 300. The user maypull out the gripping parts as needed and hold the portable informationdevice 300 stably with them.

FIG. 17 is a front view of a portable information device 400 accordingto a second variation of the second embodiment. Only a difference withFIG. 13 is described herein. In this variation, upper left corner andupper right corner of the casing and the center board 250 projectingfrom the casing have a round shape. Thus, there is same advantage withthe first variation in regard to the operation of the left shoulderswitch 226 and the right shoulder switch 228. In this variation, lowerright corner and lower left corner of the casing and the center board250 projecting from the casing are formed substantially right angle samewith the portable information device 200 in FIG. 13. Hence, holdingstability of the casing by the user is not decreased at these corners.

FIG. 18 is a front view of a portable information device 500 accordingto a third variation of the second embodiment. Only a difference withFIG. 13 is described herein. This portable information device 500comprises container part 332. The casing and the central board 250comprises sliding mechanism (not shown). As shown in FIG. 19, left wingand right wing of the casing and the central board 250 may slide to beaccommodated into the container part 332. By this mechanism, theportable information device may change its size to small one forcarriage, increasing its portability. In addition, since all theoperation mechanism such as the small stick 212, the analog/digitalselecting switch 214, the main buttons 216 are housed into the containerpart 332, false operation may be prevented during carriage.

The present invention has been described based on some embodiments. Suchdescription is for illustrative purposes only. Thus, those skilled inthe art would understand that various variations may be made incombinations with the components and such variations are within thescope of the present invention. An arbitrary combination of thecomponents described in the embodiments is also effective as anembodiment of the present invention.

While the portable electric device or the portable information devicehave been described in the embodiment, the structure or the arrangementof the buttons according to the invention may be also applicable to acontroller for a stay-at-home type game machine.

INDUSTRIAL APPLICABILITY

According to the present invention, the operability of a portableelectronic device may be improved.

1. A portable electronic device, comprising: a casing, both ends ofwhich are capable of being gripped by a user's both hands, respectively;a display unit fitted onto the face of the casing; operation devicearranged to operate an object in the image displayed on the displayunit; left-hand area and right-hand area on which the operation deviceis located, respectively; a home button is located in an area sandwichedbetween the left-hand area and the right-hand area, the home buttonbeing arranged to put the image displayed on the display unit back to amain screen.
 2. The portable electronic device of claim 1, wherein thehome button is located below the display unit.
 3. The portableelectronic device of claim 1, wherein the home button is located withinan area constituted to be tactilely or visually distinct from theleft-hand area and the right-hand area.
 4. The portable electronicdevice of claim 1, wherein the operation device comprises an analogoperation device operated by a thumb of the user gripping the casing,the analog operation device being arranged to output an analog signalfor direction of the object.
 5. The portable electronic device of claim4, wherein the operation device comprises a direction instruction keyoperated by a thumb of the user gripping the casing, the directioninstruction key having a plurality of pressing faces each correspondingto an operation direction thereon.
 6. The portable electronic device ofclaim 5, wherein the center of the analog operation device is locatedinwardly than the center of the direction instruction key.
 7. Theportable electronic device of claim 4, wherein the operation devicecomprises a plurality of button keys operated by a thumb of the usergripping the casing, the plurality of button keys each outputting singleinstruction